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May 19, 2009 -- Men who take the drug Flomax within two weeks of cataract surgery are at risk of serious eye complications, including a detached retina or lost lens, according to a new study published in the Journal of the American Medical Association.

Flomax is a commonly prescribed medication used to treat urination difficulties brought on by an enlarged prostate, or benign prostatic hyperplasia (BPH). The condition affects nearly three out of four men by age 70, according to background information in the journal report.

Flomax is a type of medicine called an alpha-blocker, which relieves BPH symptoms by targeting receptors that relax smooth muscles along the urinary tract. However, the same receptors are located in the smooth muscle of the iris in the eye. Some small studies have suggested that Flomax may make a man more likely to develop intraoperative floppy iris syndrome (IFIS), which increases the risk of cataract surgery-related complications. But data from larger studies are lacking.

For the current study, Chaim M. Bell, MD, PhD, of St. Michael's Hospital in Toronto, Canada, and colleagues analyzed medical records of 96,128 men 66 and older who had cataract surgery between 2002 and 2007. They determined which men took Flomax or a similar drug at the time of cataract surgery and who experienced a cataract surgery complication.

They grouped the men into two categories:

Recent exposure group: Men who had taken Flomax or other alpha-blocker within 14 days of cataract surgery. Most men -- nearly 11,000 -- fell into this group.

Previous exposure group: Men who had a history of taking Flomax or another alpha-blocker but not in the 14 days before cataract surgery.

The researchers discovered that 284 men (0.3%) had a complication in the 14 days following cataract surgery. Those who took Flomax two weeks before the procedure were 2.3 times more likely to have a serious complication.

Among the complications:

175 men had a procedure for a lost lens or lens fragment

35 men had a retinal detachment

26 men had both

100 men had suspected inflammation within or around the eye, a condition called endophthalmitis

Taking Flomax more than 14 days before surgery did not appear to increase a man's risk for cataract surgery complications, nor did previous exposure to other alpha-blockers.

"Because the combination of cataract surgery and [Flomax] exposure is relatively common, patients should be properly apprised of the risks of drug therapy, and preoperative systems should focus on the identification of [this drug's] use by patients. In this way, surgeons can plan and prepare for a potentially more complicated procedure or refer to someone with more experience," the authors conclude in the journal article.

In an accompanying editorial, Alan H. Friedman, MD, of the Mount Sinai School of Medicine, New York, calls for close reassessment of Flomax's safety data to determine if a black box warning is warranted.

"Cataract surgery is the most commonly performed operation in the United States today. With nearly 2 million cataract operations performed in the United States each year, the magnitude of [intraoperative floppy iris syndrome or] IFIS associated with [Flomax] cannot be underestimated." he writes.

"Although the prescribing information for [Flomax] includes IFIS as a 'general precaution,' the data on the risk of this complication should be reassessed to determine whether a 'black box' warning should be issued to caution the ophthalmic surgeon and the general public (men in particular) of danger to the eye of taking [alpha-blockers] before cataract surgery."